Pottery making



May 23, 1933. A, F BROTZ 1,911,011

POTTERY MAKING Filed Dec. 26, 1930 5 Sheets-Sheet 1 WITN SSES V g (1 I,-u

ATTORNEY A. F. BROTZ POTTERY MAKING May 23, 1933.

Filed Dec. 26, 1930 5 Sheets-Sheet 2 FIG&

INVENTOR ATTOQ N E g May 23, 1933.

A. F. BRQTZ POTTERY MAKING Filed Dec. 26, 1950 5 Sheets-Sheet 3 FIG. 6

FIG. 5

FIG. 8

Lw INVENTOR EIG. 7

I I WITNESSES ATTORNE May 23, 1933. BRQTZ 1,911,011

POTTERY MAKING Filed Dec. 26, 1930 5 Sheets-Sheet 4 FIG. 8 III-c1. 1O

245 INVENTOIQ WITNESSES a w V. Ii

W A-ra-R Patented May 23, 1933 UNITED STATES T ,F ICE ANTON FRANKBRO'IZ, OF KOHLER, WISCONSIN, ASSIGNOR TO .KOHLER COMPANY, OF KOHLER,WISCONSIN, A CORPORATION OF VIISCONSIN POTTERY MAKING Application file'dDecember 26, 1330. :Serial No. 504,826.

This invention .has for its object to produce for the kiln, potteryplumbing ware or the like, such as bathtubs, lavatories, Water closets,and so forth, by pressure.

The present method of producing such enough to stand alone for treatmentin the drier kiln and the baking kiln. This drying in the mold requiresconsiderable time even though the mold is made up of thick plaster ofParis Walls in order to draw the Water fromthe clayand expedite thedrying. Large floor space is required to accommodate the filled moldsduring the drying period of something like twenty-four hours.

It is the object of the present invention to avoid all of this delay andstorage space for drying in the molds by squeezing the clay in metalmolds under a very high degree of pressure using only sufiicientmoisture in thepowderedclay with which the molds are filled to cause itto bindunder such pressure and per- .mit the article tobe immediatelyejected from .the mold containing only that amount of moisture that iscontained by thearticle produced by the old method. Thus the steps of.30 filling the mold, subjecting it to pressure to fornithe article,stripping it from the mold and introducing it into the drier and bakingkilns follow each other successively Without loss of time andmayconstitute a continuous 3 operation.

Another object of the inventionris to perfeet details of construction ofthe mechanism usedforcarrying out this method.

lVith the above and other objects in view the invention consists inthemethod and apparatusformaking pottery as herein claimed and allequivalents.

Referring to the accompanying drawings, in whiclrlike characters ofreference indicate the sameparts in different views,

Fig. 1 is ageneral sectional front elevation of the apparatus used incarrying out the pottery making method of this invention;

Fig. 2 is a plan view thereof With parts sectioned on the plane ofline22 of'Fig. 1;

.a sectionof thetrackQQ maybe ,rails 25 carried'on the .platformofa car26 Fig. 3 is a side elevation .of the press with the mold ,in positionto receive pressure;

Fig. AL is a side elevation-of the extractor with the mold in positiontherein;

Fig.5 is a detailsectional view-of the mold as itIenters ,the press,having been .filled With moist granular clay and having had :thebottonrforming die placed thereon;

Figs-6, 7 and 8 are detail sectional views of successive steps .ofoperation .ofqthe .press on the mold;

Figs. 9 and 10 are sectional elevations ,of the extractor before .andafter removing .the outsidedie with clay article from the inside die;

Figs. 11,12 and 13 are sectionaldetailviews of successive positions ofthe extractor in stripping the article from the mold, and

Fig. 14 is a diagram showing the successive stepsofthe this invent-ion.

In these drawings, 20 represents Wheeled trucks, eachihavingpermanentlyand rigidly fastened on it aninside die 21 shaped to correspondWith-.theinsideof ,the article being manufactured. The article chosenfor the purpose of illustration is a flushing tank, though bathtubs,.lavatories, Water closets and the like pottery plumbingare orotherarticles may be made instead. The trucks 20 travel on elevated tracks 22connecting a hyd raulic press 23 and ,ahydraulic extractor 24.

For convenience in supplying the trucks with their molds conditioned.for squeezing, formedby traveling on a track27. The assembling andfilling of the molds may bedoneat a convenient distance and then thecarsbearing thememay be brought into-register with the tracks 22 and thetrucks run first {to the press.-andthentothe extractor and thenback tothe carand then conducted away to-repeat.

Referring to Fig. 5, it will .be observed that the inside dielQl has,ashoulder 28 entirely surrounding it and upon this shoulder rests asegmental strippingringQS). An. outside die '30-restson supporting pins,31, which arepivotally mountedon the :baseof theinside die and which arereceived in'notches in pottery making method of the upper edge of thelower edge of the outside die. The stripping ring 29 just fits withinthe outside die 30, and shoulder 28, being of the same size and shape,is capable of doing likewise, but as long as the supporting pins 31stand upright the outside die is prevented from telescoping the shoulderand its lower edge is at the top of the shoulder and the bottom of thestripping ring. The stripping ring serves to space the inside die fromthe outside die and is therefore of the thickness of the walls of thearticle to be produced.

hen the parts are so assembled the top of the outside die is very muchhigher than the top of the inside die and into this space and the moldcavity between the dies is poured the material of which the article isto be made. This material is in granular or powdered form asdistinguished from the liquid or plastic condition in which it has beenpreviously molded and consists of clay which has been ground in a tubemill or the like and to which a definite amount of moisture has beenadded in a mixer so that it is merely damp. To give an idea of thedegree of moisture added to the clay so that it is merely damp it may besaid that it contains the proper degree of moisture for the purpose whena handful, squeezed in the hand, will just form a ball, as there is justsufficient moisture present to cause it to cohere under the pressurethat can be exerted by the hand. The proper degree of moisture is whatis known in the art as between stiff and half stiff. Instead of addingmoisture, the clay may be dried only to a point where it contains theproper amount of moisture and then ground and used without beingsprayed.

The mold cavity is filled with this damp clay, a predetermined quantitythereof being used as by striking it off flush with the top of theoutside die. A bottom-forming die 32 of a size and shape to just lit inthe upper end of the outside die is placed thereon and constitutes aplunger for exerting pressure upon the entire body of clay.

The inside die 21, the outside die 30, to-

' gether with the stripping ring 29 for spacing them apart, and thebotton'i-forming die 32,

constitute the mold and are all formed of heavy metal capable ofwithstanding greatpressure without distortion.

The mold prepared in this manner, as shown in Fig. 5, is conducted tothe press 23, as before mentioned, where its truck is engaged by thepress head and the entire truck and mold are lifted thereby, bringingfirst the bottom-forming die 32 against the overhead reaction member andthen forcing same within the outside die until the outside die engagesthe reaction member of the press, as shown in Fig. 6. Pressure thenreleased slightly, permitting the supporting pins 31 to be swung outfrom beneath the outside die, is shown in Fig. 7, and then pressure isagain applied, causing the outside die to telescope the shoulder 28 andengage the base as shown in Fig. 8. When this position of the parts isreached the mold cavity has been contracted to the size of the finishedarticle and the clay has been compressed at the sides as well as at thetop, or what is the bottom of the article, so that it is ofsubstantially uniform density throughout. This pressure in actualpractice on articles as illustrated reaches as much fourteen hundredpounds per square inch. Having locked thestripping ring 29 by means ofhand sci-e vs 51 in its new position within the outside die, to which ithas been moved by the action of the press, it is then necessary totransfer the mold to the extractor 24 to extract the article therefrom,and for this purpose the press head 23 is lowered, returning the truckto the track on which it is shuttled over to the extractor 24.

On entering the extractor the truck edges pass beneath stationary hooks34, as shown in Fig. 4, which hooks are fixed in position and serve toprevent the truck from being lifted from the rails with the liftingaction e:-;erted on the outside die when stripping the article from theinside die.

Besides the stationary hooks 34 that are securely fastened to beams 35of heavy rigid framework 36, the extractor, as shown in Figs. 1 and 4,comprises a hydraulic cylinder 37 having its piston 38 carrying arectangular lifting frame 39, which is guided by rollers 4O bearing onuprights of the frame 36. Swinging hooks 41 mounted on the upperhorizontal beam of lifting frame 39 engage with lifting lugs 42 formedon the outside die 30. Also a ram 43 is slidably mounted in a verticalguide 44 on the rigid frame 36 and carries at its lower end a ram headwith openings suitable for receiving a pair of upstanding lugs 45 on thebottom-forming die 32 while wedges 46 driven through transverse openingsin said lugs securely lock the ram head to the bottom-forming die. Awire cable 47 suspends the ram 43 by passing around pulleys 48 andcarries a counterweight 49 and a handle rod 50 by means of which the rammay be raised or lowered.

On being admitted to the extractor the truck becomes engaged by thestationary hooks 34, as explained. Then the lifting frame 39 is loweredand the lifting hooks 41 engaged with the lugs 42 of the outside die andthe ram 43 is lowered and the ram-head is locked on the lugs 45 of thebottom-forming die 32 so that parts are in the position shown in Fig. 9.Now the lifting frame 39 is raised by the hydraulic cylinder and theoutside die with the molded article is stripped from the inside die, asshown in Fig. 10, the stripping ring 29 compelling the article to remainwith the outside die as the parts of the mold are separated. The truckwith the insidedie is non removed and the hand screws 51 are then turnedto unlock the stripping ring and said stripping ring is removed, asshown in Fig. 11. At this stage it is usua to cut or punch the variousopenings in the clay article that are required, templates being used asguides for this purpose.

A stationary table 52 then has placed upon it in a predeterminedposition a supporting frame comprising a light hollow core-likesupporting rack 53 detachably mounted on a base 54, the rack having bailhandles 55 by which it is attached to the base, and having aspring-pressed plun er 56 at its top forming a light cushioning bearingsurface. In the spotted position of the supporting frame it is directlybeneath the suspended mold and the latter is then lowered thereon bylowering the lifting frame 39 to a position, as shown in Fig. 12, inwhich the clay article is almost seated on the supporting frame. The ram43 is now locked by inserting a pin 57 through an opening thereof, asshown in Fig. 13, so that it will prevent upward movement of the ram.The lifting frame 39 is then raised to lift the outside die 30 while theram with the bottom-forming die 32- remains stationary, thus strippingthe outside die from the work and permitting the work to drop lightlyupon the spring plunger of the supporting frame without injury. A slightdraft may be given the mold cavity to facilitate the stripping of theinside die and of the outside die.

The molded article may now be removed on its rack and subjected to theusual trimming and slicking operations that are performed by hand andmay have the outlet opening punched in the bottom, if this has not beenformed by the dies, so as to complete it for immediate admission to thedrying and baking kilns. 7

It is of the same moisture content and degree of plasticity as the curedproduct that has been poured as a liquid clay slip and allowed to dryand harden in plaster of Paris molds, but instead of requiring the longperiod of drying it has been produced at once. The very high degree ofpressure to which it has been subjected serves to cause the clay tocohere with only that degree of moisture that the slip product containsafter drying in plaster of Paris molds. On account of the fluid natureof the granular clay material used and the fact that pressure is appliedfirst at the larger end of the mold cavity and then at the other thematerial itself as well as the pressure to which it is subjected isevenly distributed throughout the body with the result that all portionsof the wall of the compressed article are of the same density and of thesame degree of dryness.

The article is able to stand alone and to evenbear the weight of otherarticles placed upon it, as is customary in kiln practice. It isimmediately subjected to drier kiln action after being stripped from themold and receiving the hand trimming and slicking, for the rack onlyremains within it during these hand operations as a means for moving itfrom place to place and for turning it while being thus handled.

It is to be understood that the pressure to which the material issubjected is not for squeezing water out of the material. No water isforced from-it during the compressing operation for there isinsufficient moisture present to permit thereof. The material, ascompared with the liquid slip previously used, may be considered as dry,but, as previously explained, it is dampened by an atomized spray ofmoisture in a mixer to uniformly dampen it so that the pressure willcause it to cohere. Vfhen stripped from the mold the surface is smoothand dry to the same extent as with articles that'have cured the fulltime in plaster of Paris molds.

lVhen the finished article is removed from the extractor on its rack andthe supporting frame is removed from the table the truck with the insidedie is returned, the stripping ring is replaced thereon, and the liftingframe 39 is lowered to lower the outside die in place on the pins 31,which have been raised for that purpose. The handle rod 50 is pulleddownwardly to lift the bottom-forming die so that it can be removed andthe truck is then rolled back to the car and taken to a convenient placefor refilling the mold. The next mold, which in the meantime has beensubjected to the action of the press 23, is then ready to be run intothe extractor and the stripping operation is repeated.

The method of producing clay forms for pottery making in accordance withthis invention is represented diagrammatically in Fig. 14, wherein 60 isa grinder by which clay is pulverized to powder, 62 is a mixer toagitate the fine clay powder while it is be ing homogeneously dampenedor moistened by an atomizer 63, 23 is the press for compressing it in amold to a solid mass, 24 is the extractor for stripping the clay articlefrom the mold as a self-sustaining form, 64 is a kiln in which the formis dried, and 65 is a kiln in which it is baked.

The press-ed molded clay articles formed in accordance with thisinvention are equal or superior in quality to those produced by the useof liquid clay slip in plaster of Paris molds, though they are producedwithin a few minutes as compared With the several days necessary for theothers, with the great saving in expense incident to the avoidance ofstorage space necessary for drying within the molds and drying the moldsthemselves. This is primarily due to the avoidance of moisture in excessof that'required to cause the clay to cohere in a solid mass capable ofsustaining itself during kiln drying and firing. The cost as well as thetime is greatly reduced, making possible continuous quantity production.

What I claim as new and desire to secure by Letters Patent is:

1. The method of producing pottery which consists in pulverizing dryclay, then dampening this granular material by subjecting it to anatomized spray while being agitated until it is neither dry nor plasticbut will just cohere to form a ball when compressed in the hand, thenplacing this damp granular clay in molds and subjecting it to pressureto cause it to cohere and form a solid body having a slippery moistsurface, then stripping the clay body from the mold and baking it in akiln.

2. The method of producing pottery ware which consists in compressing ina mold damp granular clay between stiff and half stiff until it coheresto form a solid article that is self-sustaining, and then baking theself-sustaining article in a kiln.

3. The method of producing clay pottery ware in the raw state ready forintroduction to a kiln for drying and baking which consists incompressing pulverized damp granular clay material of a consistencybetween stiii and half stiff in a mold to a degree at which the claycoheres to form a solid self-sustaining article having a slippery moistsurface.

4;. In the art of manufacturing pottery ware, the step of producingself-sustaining molded clay articles ready for treatment in the kiln,without the use of moisture-absorbing molds and the delay incidentthereto, which step consists of compressing in molds granular dampenedclay material containing only that degree of moisture that will causethe clay to cohere and form a ball when compressed in the hand.

5. The method of producing pottery from granular moist clay whichconsists in compressing the clay within a mold by applying pressurefirst at one end of the mold and then at the other.

6. The method of producing pottery from granular moist clay whichconsists in compressing the clay within a mold having a mold cavitylarger at one end than at the other by applying pressure first at thelarger end of the mold cavity and then at the other.

7. The method of producing hollow ware pottery having a bottom and sidewalls from granular moist clay, which consists in compressing the claywithin a mold having a mold cavity corresponding with the bottom andside walls of the hollow ware by applying pressure first at thebottom-forming end of the mold cavity and then at the other end.

, 8. The method of producing hollow ware pottery having a bottom andside walls from granular moist clay, which consists in compressing theclay within a mold having a mold cavity corresponding with the bottomand side walls of the hollow ware by applying pressure first at theoutside of the bottomfo'rming end of the mold cavity and then at theinside of the bottom-forming end of the mold cavity.

9. An independent portable mold for forming pottery by subjecting moistgranular clay to pressure, comprising an outside die, and end memberstelescoping therewith for movement relative thereto for compressing thematerial from both ends when subjected to the action of a press. 7

10. An independent portable mold for forming pottery by subjecting moistgranular clay to pressure, comprising an outside die. end memberstelescoping therewith for movement relative thereto for compressing thematerial from both ends when subjected to the action of a press, andmeans for temporarily preventing the telescopic movement of one on dmember for causing the end members to act successively in compressingthe material.

11. A mold for forming pottery by subjecting moist granular clay topressure, comprising an outside. die, end members positioned formovement relative thereto for compressing the material from both endswhen subjected to the action of a press, and supporting pins pivotallymounted on one of the end members and engaging the outside die'fortemporarily preventing the relative movement therebetween and causingthe end members to act successively in compressing the material.

12. An independent portable mold for forming hollow ware pottery bysubjecting moist granular clay to pressure, comprising an outside die,and an inside die and a bottom-forming die telescoping therewith atopposite ends for compressing the material between them.

13. A mold for forming hollow ware pottery by subjecting moist granularclay to pressure, comprising an outside die, an inside die and abottom-forming die telescoping therewith at opposite ends forcompressing the material between them, there being a shoulder on theinside die to form the tele scoping fit with the outside die, asectional stripping ring on said shoulder fitting between the inside dieand the outside die, and means for locking the stripping ring to theoutside die.

14. A mold for forming hollow ware pottery by subjecting moist granularclay to pressure, comprising an outside die, an inside die and abottom-forming die telescoping therewith at opposite ends forcompressing the material betweenthem, there being a shoulder on theinside die to form the telescoping fit with the outside die, a sectionalstripping ring on said shoulder fitting bethe material between them, andan tween the inside die and the outside die, and supporting pinspivotally mounted on the inside die for engaging the outside die toprevent the telescoping movement between them.

15. Mechanism for forming hollow ware pottery by subjecting moistgranular clay to pressure, comprising an Outside die, an 1nside die anda bottom-forming die telescoping therewith at opposite ends forming acontracting mold for compressing the material, a wheeled truck carryingthe inside die, a track on which the truck travels, and a press having aplunger for lifting the truck and mold from the track and having areaction member for engaging the bottom-forming die and the outside die.

16. Mechanism for forming hollow ware pottery by subjecting moistgranular clay to pressure, comprising an outside die, an in side die anda bottonrforming die telescoping therewith at opposite ends forming acontracting mold for compressing the material, there being a shoulder onthe inside die to form the telescoping fit with the outside die,

a sectional stripping ring on said shoulder fitting between the insidedie and the outside die, a wheeled truck carrying the inside die, atrack on which the truck travels, and a press having a plunger forlifting the truck and mold from the track and having a reaction memberfor engaging the bottom-forming die and the outside die.

17. Mechanism for forming hollow ware pottery by subjecting moistgranular clay to pressure, comprising an outside die, an inside die anda bottom-forming die telescoping therewith at opposite ends forcompressing the material between them, a wheeled truck on which theinside die is fast, a press receiving the truck for pressing the diestogether to compress the material between them, and an extractor forreceiving the truck from the press, comprising stationary membersengaging the truck for holding the inside die against movement,apressure-operated lifting member, means thereon for engaging the outside die for lifting it from the inside die with the compressed clayarticle moving therewith, a ram engaging the bottomforming die, andmeans for locking the ram whereby movement of the outside die ejects thecompressed clay article therefrom.

18. Mechanism for forming hollow ware pottery by subjecting moistgranular clay to pressure, comprising an outside die, an inside die anda bottom-forming die telescoping therewith at opposite ends forcompressing the material between them, there being a shoulder on theinside die to form the telescoping fit with the outside die, a strippingring on the shoulder, a wheeled truck on which the inside die is fast, atrack on which the truck travels, a press receiving the truck andpressing the dies together to compress extractor for receiving the truckfrom the press comprising stationary members engaging the truck forholding the inside die against movement, a pressure-operated liftingmember, means thereon for engaging the outside die for lifting it fromthe inside die, a ram engaging tho bottom-forming die, and meansforlocking the ram whereby movement of the outside die'ejects thecompressed clay article therefrom.

l9. Mechanism for forming hollow ware pot ery by subjecting moistgranular clay to pressure comprising an outside die, an inside die and abottran-forming die telescoping therewith at opposite ends forcompressing the material between them, there being a shoulder on theinside die to form the telescoping fitwith the outside die, a sectionalstripping ring on said shoulder fitting between the inside die and theoutside die, a wheeled truck on which the inside die is fast, a track onwhich the truck travels, a press receiving the truck and pressing thedies together to compress the material between them, means for lockingthe stripping ring'in the position to which it is moved by the operationof the press, an extractor for receiving the truck from the presscomprising stationary members engaging the truck for locking the insidedie against movement, a pressureoperated lifting member, means thereonfor engaging the outside die for lifting it from the inside die with thecompressed clay article moving therewith and engaged by the strippingring, a ram engaging the bottom-forming die, and means for locking theram whereby movement of the outside die ejects the compressed clayarticle after the stripping ring is removed.

20. Mechanism for forming hollow ware pottery by subjecting moistgranular clay to pressure comprising an outside die, an inside die and abottom-forming die telescoping therewith at opposite ends forcompressing the material between them, an extractor comprisingstationary means for engaging the inside die to prevent movementthereof, a pressure-operated lifting member having means for engagingthe outside die for lifting it from the inside die with the compressedclay article moving therewith, a ram engaging the bottom-forming die,means for locking the ram whereby movement of the outside die causes thebottom-forming die to eject the compressed clay article, and a racksubstituted for the inside die for receiving the article as it isejected.

21. Mechanism for forming hollow ware pottery by subjecting moistgranular clay to pressure comprising an outside die, an inside die and abottom-forming die telescoping therewith atopposite ends for compressingthe material between them, an extractor comprising stationary means forengaging the inside die to prevent movement thereof, a

pressure-operated lifting member having means for engaging the outsidedie for lifting it from the inside die with the compressed clay articlemoving therewith, a ram engaging the bottom-forming die, means forlocking the ram whereby movement of the outside die causes thebottom-forming die to eject the compressed clay article, a racksubstituted for the inside die for receiving the article as it isejected, anda spring cushion on the rack to engage the bottom of thearticle on the inside thereof.

22. In the art of manufacturing vitreous china plumbing ware, the methodof producing articles in the raw state of the same consistency andphysical characteristics as articles produced from liquid clay slip andallowed to dry to a pre-determined moisture content by having the waterabsorbed therefrom by plaster of Paris molds, which-consists ofgranulating dry clay material, adding water thereto to give such ganularclay material said pre-determined moisture content, and then subjectingsuch ganular clay material of pre-determined moisture content topressure within molds.

In testimony whereof, I affix my signature.

ANTON FRANK BROTZ.

